So I think its more that u want to bet hands that retain equity equity vs a calling range. And also hands that have good properties on later streets: blockers, cooler calling ranges, etc.
In the A3 hand, we have 5 outs vs top pair, and we turn 2 pair on the Ace which is a good barrel card for use where it may look like we have AK and get max value from 78?
In the 54 hand, we turn boat loads of equity on so many turns we don’t even care, just blast it off
As for what Clarke says, "Showdown Value is of the vulnerable sort and so should be protected.”this is pretty much nonsense since we’re not ever going to showdown. Like it just doesn’t matter that we have showdown value when were gonna pump up the pot to a point where a pair of 5s never wins. However I still think its a bet for 2 reasons:
1. To make our opponent fold out their equity share of the pot.
2. Because we have solid equity vs a calling range.
"In my poker study in the past I remember reading that betting for protection is an invalid reason to bet and we should only either be betting for value or betting to get better hands to fold. “
This is also nonsense imo, unless were talking exactly about the river (in which case A+) and see my above points.